From 9083977dabf3833298ddcd40dee28687f1e6b483 Mon Sep 17 00:00:00 2001 From: Sahitya Tummala Date: Mon, 4 Feb 2019 13:36:53 +0530 Subject: [PATCH] f2fs: do not use mutex lock in atomic context Fix below warning coming because of using mutex lock in atomic context. BUG: sleeping function called from invalid context at kernel/locking/mutex.c:98 in_atomic(): 1, irqs_disabled(): 0, pid: 585, name: sh Preemption disabled at: __radix_tree_preload+0x28/0x130 Call trace: dump_backtrace+0x0/0x2b4 show_stack+0x20/0x28 dump_stack+0xa8/0xe0 ___might_sleep+0x144/0x194 __might_sleep+0x58/0x8c mutex_lock+0x2c/0x48 f2fs_trace_pid+0x88/0x14c f2fs_set_node_page_dirty+0xd0/0x184 Do not use f2fs_radix_tree_insert() to avoid doing cond_resched() with spin_lock() acquired. Signed-off-by: Sahitya Tummala Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/trace.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/fs/f2fs/trace.c b/fs/f2fs/trace.c index ce2a5eb210b6..d0ab533a9ce8 100644 --- a/fs/f2fs/trace.c +++ b/fs/f2fs/trace.c @@ -14,7 +14,7 @@ #include "trace.h" static RADIX_TREE(pids, GFP_ATOMIC); -static struct mutex pids_lock; +static spinlock_t pids_lock; static struct last_io_info last_io; static inline void __print_last_io(void) @@ -58,23 +58,29 @@ void f2fs_trace_pid(struct page *page) set_page_private(page, (unsigned long)pid); +retry: if (radix_tree_preload(GFP_NOFS)) return; - mutex_lock(&pids_lock); + spin_lock(&pids_lock); p = radix_tree_lookup(&pids, pid); if (p == current) goto out; if (p) radix_tree_delete(&pids, pid); - f2fs_radix_tree_insert(&pids, pid, current); + if (radix_tree_insert(&pids, pid, current)) { + spin_unlock(&pids_lock); + radix_tree_preload_end(); + cond_resched(); + goto retry; + } trace_printk("%3x:%3x %4x %-16s\n", MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev), pid, current->comm); out: - mutex_unlock(&pids_lock); + spin_unlock(&pids_lock); radix_tree_preload_end(); } @@ -119,7 +125,7 @@ void f2fs_trace_ios(struct f2fs_io_info *fio, int flush) void f2fs_build_trace_ios(void) { - mutex_init(&pids_lock); + spin_lock_init(&pids_lock); } #define PIDVEC_SIZE 128 @@ -147,7 +153,7 @@ void f2fs_destroy_trace_ios(void) pid_t next_pid = 0; unsigned int found; - mutex_lock(&pids_lock); + spin_lock(&pids_lock); while ((found = gang_lookup_pids(pid, next_pid, PIDVEC_SIZE))) { unsigned idx; @@ -155,5 +161,5 @@ void f2fs_destroy_trace_ios(void) for (idx = 0; idx < found; idx++) radix_tree_delete(&pids, pid[idx]); } - mutex_unlock(&pids_lock); + spin_unlock(&pids_lock); } -- 2.30.2